The U.S. National Arboretum is a U.S. Department of Agriculture research and education facility and a living museum. It is dedicated to serving the public and improving our ...

The National Library of Medicine (NLM), on the campus of NIH in Bethesda, Maryland, is the world's largest medical library. It collects materials in all major areas of the health sciences and to a lesser degree in such areas as chemistry, physics, botany and zoology. The collections stand at 5 million items--books, journals, technical reports, manuscripts, microfilms, photographs and images. Housed within the Library is one of the world's finest medical history collections of old (pre-1914) and rare medical texts, manuscripts, and incunabula.

Online Dictionary - Multiple dictionaries including: English dictionary, medical dictionary, legal dictionary, financial dictionary, computer dictionary, thesaurus, dictionary of acronyms and abbreviations, dictionary of idioms, thesaurus, Columbia encyclopedia, Wikipedia encyclopedia, Hutchinson encyclopedia, examples from classic literature, pronunciations, word browser, glossary. Free access

Invasivespeciesinfo.gov -- Reference gateway to information, organizations and services about invasive species; including Federal, State, local, and international sources.